(CBS NEWS) – Darren Criss’ visit to late-night TV on Thursday turned emotional when Conan O’Brien asked him how he and the rest of the “Glee” cast members were holding up in the wake of Cory Monteith’s death.

“Obviously it’s been a very rough time,” the San Francisco-born Criss said on “Conan,” adding, “We’re picking up the pieces now and there’s two things you got to remember about Cory — one, he was a really funny guy. He had a great sense of humor; he loved life. He always took care of his friends, he wanted his friends to be happy, so it’s only right that we try and start to smile again, try and laugh again. It’s something he would have wanted.”

Criss, 26, said, “On a personal note, he will be severely missed but I’m just happy that a guy like him got to touch as many lives as he did while we were all lucky enough to have him.”

Several fellow “Glee” stars, including Lea Michele, have spoken up about the loss of Monteith, who died July 13 at age 31 from a mixed drug toxicity involving heroin and alcohol. But as Criss said, the cast will have to pick up the pieces as season 5 shooting gets under way this month, with the series premiere scheduled for Sept. 26.

Fox entertainment president Kevin Reilly said Thursday that Monteith’s character, Finn Hudson, will be written out of the show in the third episode: “That is the episode where Cory’s character will be written off and will deal directly with drug addiction and with the circumstances surrounding Cory’s death.”